[Arm-netbook] MNT Reform Campaign

[David Niklas]

On Wed, 13 May 2020 21:52:34 +0200
Paul Boddie <paul at boddie.org.uk> wrote:
> On Tuesday 12. May 2020 19.20.37 Christopher Havel wrote:
<snip>
> > (1) Why are there none of these OSHW devices using existing
> > x86-compatible CPUs/SoCs?
<snip>
> > (2a) Are there any meaningful barriers to creating an OSHW-compatible
> > x86 CPU/SoC, independent of major chip houses (Intel, AMD) or
> > established niche players (VIA, etc)?
<snip>
> > (2b) I've heard noises of a homegrown sort of effort out of China,
> > from a company and fab house over there... could that CPU be
> > considered as an acceptable candidate for such an effirt, and if not,
> > why...? (I assume not, and because "China!", but I'm wide open
> > here.)
<snip>

The Chinese have a deal with Via which bought out Cyrix which had been in
a patent ware with Intel as they used hard-coded instructions whereas
Intel and AMD used micro-code to decode instructions.
https://www.youtube.com/watch?v=iWGAdoMz1c0

As to why there are no competitors in the X86 space, the amd64 64-bit
extensions are patented AFAIK. So you're limited to a 32 bit system.
That's not to mention MMX, SSE, AVX, and an assortment of other
instructions throughout the years.

Then there's the amount of design you have to do just for the
instruction set. Its hysterical how many instructions for moving data
there are.
https://www.youtube.com/watch?v=g9_FYRAfyqQ

Then you need something with high enough speed to match or exceed
the speed of the competition, without voiding any of their patents,
which is something they can't even achieve.

Then you need to create masks for the lithography for fabricating these
chips. Luke says a small opensource RISC-V CPU would cost millions to
create the masks for on an old node -- 32nm IIRC. 7nm costs double the
amount that 16nm costs for chip fabrication according to AMD which places
it in the hundreds of millions for the masks; and you need more for 7nm
then previous nodes.

You also have to have really good power usage, as 7nm is so small that you
have almost no space left for thermal conductivity. In fact, current AMD
offerings are thermally limited in the silicon. They could clock higher
and use more power but they'd blow through their thermal envelope.

Also, according to AMD, "extreme" measures must be taken to see to it that
clock speeds remain high instead of going lower then previous offerings.

You need to have enough transistors per mm2.

You need enough cores, memory channels, and PCIe 4.0 lanes.




In summery:

What you should be asking is, "Why are there no OSHW CPUs/GPUs for
purchase by consumers at all?"

In short, the Parallela board used a Xilinx (closed source HW and SW),
FPGA for their Epiphany CPU and said that they couldn't make it in
silicon due to lack of demand coupled with expense.
When people demand OSHW, they will get it. Until then, its going to be
based solely on the kindness of the companies and developers, like luke.
Gooooooo Luke!!!

Sincerely,
David